The term "cash flow" is widely used in the economic literature. However, there are discrepancies in the wording of its definition. The article discusses approaches to the study of cash flows, a comparative description of the static and dynamic approaches in the theory and practice of management is made. Considering the variety of cash flows and approaches to their study, the article also analyzes the existing classifications and proposes typologies in the author's interpretation. The main provisions for the effective management of cash flows are outlined, and conclusions are drawn about the economic essence of this concept.